Utilize his knowledge

I would suggest utilizing his knowledge to achieve your targets. If this person feels exciting, I would advise you to publicly recognize and utilize his/her knowledge by assigning challenging assignments in his/her areas of proficiency, and therefore check how he applies and contributes his knowledge. The need to "demonstrate" his intellect will be alleviated when, with your guidance, it can be suitably used and profit your department or group. You might assign him as project lead roles in his areas of specialization, for example, and be clear about when it is suitable to work together on decision making, etc., and how you would like to be well-versed of progress, activities, etc. This way the person can be accredited for the profit he brings, and you get the pleasure of guiding his future career development. Who recognizes, this person may be of great provision to you, and also may be glad for the prospects you gave him.